COORDINATION CHEMISTRY AND SPECTROSCOPIC PROPERTIES OF SOME DIORGANOTIN(IV) COMPLEXES WITH S-DONOR SCHIFF BASE LIGANDS

Schiff bases S-benzyl-and S-methyl-beta-N-(2-hydroxyphenyl)methylene dithiocarbazate (H2L1 and H2L2, respectively) and S-benzyl-and S-methyl-beta-N-(2-chlorophenyl) methylenedithiocarbazate (HL3 and HL4, respectively) were prepared. Then organotin(IV) complexes [SnPh2(L-1)] (1), [SnMe2(L-1)] (2), [SnPh2(L-2)] (3), [SnMe2(L-2)] (4), [SnPh2Cl(L-3)] (5), and [SnPh2Cl(L-4)] (6) were obtained from the reaction of Schiff bases with SnR2Cl2 (R = Ph and Me). The synthesized complexes have been investigated by elemental analysis and IR, H-1 NMR, and Sn-119 NMR spectroscopy. Spectroscopic studies show that, in complexes 1-4, the Schiff base acts as a tridentate dianionic ligand and coordinates through the thiol group, imine nitrogen, and phenolic oxygen. The coordination number of tin is five. In complexes 5 and 6, the ligand is monoanionic and unidentate, and coordinated only via the thiol group, and the azomethine nitrogen is not involved in coordination to tin. Therefore the coordination number of tin is four.